With continuous improvement of the living standards of people, the development of urbanization and industrialization, people's eating habits have been changed, and physical activities has gradually decreased. Hyperlipidemia becomes a serious risk to human health. Hyperlipidemia is a common disease caused by abnormal lipid metabolism in the body. It mainly refers to unduly high levels of total cholesterol, triglyceride and low-density lipoprotein in serum or unduly low low-density lipoprotein level in serum. There is no obvious clinical symptom in the early stage of hyperlipidemia, and its damage to the body is nonobvious, progressive and systemic. Hyperlipidemia may accelerate atherosclerosis, and the blockage of artery will cause many diseases, such as cardiovascular and cerebrovascular diseases, kidney disease, liver disease and so on. Cardiovascular and cerebrovascular diseases are the leading cause of death in the middle-aged and elderly people and are the number one killer that threatens human health. According to the World Health Organization, about 17 million people die from this chronic disease each year, accounting for about 30% of the total global death toll. In other words, one out of every three dead people is caused by cardiovascular disease.
Modern medical studies have shown that the factors affecting human blood lipid levels mainly include genetic factors and environmental factors. However, the influence of genetic factors is limited, and blood lipid level is mainly affected by environmental factors. The environmental factors that affect human blood lipid level are as follows: (1) High cholesterol and high saturated fatty acid diet. Studies have shown that when the body takes in a lot of saturated fatty acids and high cholesterol, the cholesterol and triglyceride content in the blood will be too high, forming hyperlipidemia. (2) High-starch diet. Results of some studies suggest that when the proportion of taking-in sugar is too high, the blood glucose rises, stimulating insulin secretion, and causing hyperinsulinemia. The latter increases the synthesis of triglyceride and very low-density pre-β-lipoprotein, causing hyperlipidemia. (3) Obesity. Obesity promotes liver exporting apolipoprotein B-contained lipoproteins, which increases the generation of low-density lipoprotein and more likely cause hyperlipidemia. (4) Lack of exercise. People who are sedentary have higher plasma triglyceride concentrations than those who keep physical exercise.
Current studies have shown that the object of lowering blood lipid can be achieved by inhibiting the absorption and synthesis of lipids, or promoting the decomposition and excretion of lipids. Polyunsaturated fatty acids, including fish oil, seal oil, various vegetable oils and so on, can facilitate lowering blood lipid mainly through inhibiting the synthesis of endogenous cholesterol and triglycerides, increasing the activity of lipoprotein lipase, promoting the clearance of very low-density lipoproteins in surrounding tissues, lowering the content of triglycerides, cholesterol and low-density lipoprotein in serum, and increasing the content of high-density lipoprotein.
With the development of economy and science, people's requirements for quality of life are getting higher and higher, and they gradually realize the importance of “preventing problems before they happen” and pay more attention to health than ever before. Research on drugs and healthcare foods is a common concern of the society. The development of healthcare foods having a function of facilitating lowering blood lipid has huge market demand, broad prospects and important practical significance.